Detachable bridge unit crystal mounting



Aug. 5, 1947. s. A. BOKOVOY 2,424,963

DETACHABLE BRIDGE UNIT CRYSTAL MOUNTING Filed Dec. 6, 1943 2Sheets-Sheet l l 6 I i ATTORNEY Aug. 5, 1947. s. A. BOKOVOY DETACHABLE'BRIDGE UNIT CRYSTAL MOUNTING Filed Dec. 6, 1943 2 Sheets-Sheet 2 R.0 3%m VA mg U M Y j E 1 3 ATTORNEY Patented Aug. 5, 1947 DETACHABLE BRIDGEUNIT CRYSTAL MOUNTING Samuel Alexander Bokovoy, Verona, N. J., assignorto Federal Telephone and Radio Corporation, New York, N. Y., acorporation of Delaware Application December 6, 1943, Serial No. 513,139

11 Claims.

The present invention pertains to frequency determining units of theresonant type and more particularly to holder structures and electricaland supporting assemblies associated therewith for piezoelectricresonators, A special object of the present improvements is to producean ad vantageous form of holder and separable crystal mounting assemblyhaving a more general application than structures as heretoforeemployed. It is designed to facilitate change in the ty e of mountingpeculiar to the use of crystals var to vibration mode to meet the r nments of either high or low frequency circuits. These are of suchdistinctive design and arrange ment as to have heretofore required fullyindividual and different structural assemblies.

In accordance with my present invention there is provided an insulatingholder desirably having externally extended terminal pins and formedwith a socket or enlarged opening for the reception and enclosure ofseparable and interchangeable bridge supports or crystal mountingsprovided with electrical terminal and supporting connectionsstandardized as to spacing and connecting arrangement and arranged tocomplete the circuit connections upon assembling by means of oppositelypositioned securing screws. The employment of the separable bridgemounting supports for the crystals permits of the convenient fullmounting assembly and testing of the resonant unit externally of theholder, the ready substitution or renewal of the unit and the furtherincorporation with the standard form of holder of bridge mountingassemblies specially designed for the mounting of the crystals of variedsizes and of mounting arrangement varied in type peculiar to therequired vibration modes and frequency values. The improved arrangement,in addition, desirably provides for securing of the terminal pins byassembling of the securing screws and the bridge supports may providefor convenient spacing variation of the crystal supporting elements incertain of its mountings.

The features of the invention will be more fully understood by referenceto the accompanying drawings wherein like reference characters areapplied to the corresponding parts in the several views.

In the drawings:

Fig. 1 is a plan view of a desirable structural embodiment of theinvention with a portion of the cover plate broken away to illustratethe separable mounting unit therein.

Fig. 2 is a vertical, sectional view thereof on line 2- -2 of Fig. 1.

Fig. 3 is a detailed sectional view on line 3-3 of Fig. 1.

Fig. 4 is a perspective view showing a different form of separablemounting unit.

Fig. 5 is a plan view similar to Fig. 1 showing the assembly therewithof a separable mounting unit adapted for resilient and center support ofthe crystal.

Fig. 6 is a horizontal sectional view of the Fig. assembly.

onal view .l. a preferred th features the invention. as shown -.l '"lgs.l to 3 the container or holder of insulating material is shown as acylindrical body I formed with the enlarged opening or socket 2 ofgenerally circular contour and open at the front face of the holderbody. The opening is closed in the customary manner by a face plate 3secured by screws 4 with an interposed washer.

At opposite sides the body is formed with thickened wall portionsrecessed to receive the inner ends of the radially disposed terminalpins 6-6, the reduced end portions of which are provided with threadedapertures therethrough for the reception of the terminal and securingscrews 'l-I entering apertures 8 in the holder thickened wall portions;the latter as shown being cut away to provide the ledges 9-9 for thesupport of a separable or bridge mounting member.

.The separable bridge support or mounting unit as shown comprises aninsulating bridge or mounting bar [0 formed to support suitably spacedconducting post contacts H for engagement with the crystal electrodesand combined connectors and mounting member supports I2 of a form andspaced to register with the apertures 8 for the securing of the mountingassembly and closing of the circuit by means of the screws 1. In thedisclosed structure, the crystal 0, having the usual opposite silvercoating electrodes e engaged by resilient contacts l3 integral with orsoldered to the posts H, is end supported as adapted for high frequencyoscillation. These electrode coatings eas shown each partially cover themargin or electrode face of the crystal and extend from opposite ends ofthe crystal so that each electrode face has a noncovered area or endmarginal surface adjacent one edge portion of the crystal. Thearrangement provides for supporting engagement of the crystals bypressure engagement between the resilient contacts I3 and terminalsupporting posts H with the respective terminal supports or postsestablishing electrical connection with an oppositely positionedelectrode. The connector posts I extend through spaced holes in thebridge l5 and have their ends soldered to the intulne'd flangeextensions of the connectors l2 which are attached to the mounting barsby means of screws to threaded thereto. The outer end portions E8 of theconnectors are formed as integral extended and offset perforated ears toreceive the securing screws 5. Accordingly, removal or the screws '5permits or" the detachment of the bridge member and its associatedelectrical connectors as an assembled crystal mounting unit therebyfacilitating adjusting, testing or replacement under favorableconditions for proper maintenance. As best shown in Fig. 2 the ledgeportions t and 9 are formed to lie in separate and relatively widelyspaced vertical planes for connection with connector members positionedupon opposite sides of the bridge mounts 5 thereby to readilyaccommodate diilerent types of mountings.

In Figs. 5, 6 and 7 there is shown an application of the invention withthe incorporation of a different type of center contact crystal mountingof the kind customarily employed for low fre quencies and vibration inthe thickness mode. As therein disclosed the detachable mounting unitcomprises a yoke form of insulator bridge 25 having the central opening25 within which tl e crystal 0 is positioned. Supporting and electricalcontact engagement with the crystal electrodes is effected by axiallyaligned contact pins slidably fitted to bores in the mounting member 28and resiliently pressed into engagement with the crystal by engagementwith the adjustable spring terminal connection and the fist terminalconnection 25. The tension of the spring 25 is adjustable by screw stud2i threaded to the yoke and passed through the spring end. The end 32 ofthe connector or terminal 26 is extended and apertured to receive thescrew 7 and a cooperating supporting terminal extension is provided byan angular terminal bar 33 aperture-d to receive the opposite connectorsecuring screw l and secured to the bridge member by screw stud 32 inclamping connecting relation to the sp ing 25. The centrally and axiallydisposed terminal connectors 25 and El as positioned in the upper andlower surfaces or" the bridge mounting thus cooperate with the ledgesupporting a rangement of the standardized holder 5. The socket openingof the latter is suitably enlarged relative to many or the crystals andmountings suificiently to accommodate and protectively enclose acondenser or condensers associated with the controlled circuit.

In Fig. 4 there is shown a separable counting of a form to beinterchangeable in the holder with the afore-described forms andproviding a further known type of low frequency crystal mounting. Inthis form the terminal supporting connectors are shown at positioned tocoact with the screws 7. They are held by screws 38 threaded to theinsulated bridge 3-" and are provided with inturned flanges 39 havinglongitudinal extensions underlying a series of vertical holes ii in thebridge for engagement by and connection to varied positioned metal posts42 upon which the crystal is supported by resilient wires G l- 45soldered to the respective electrodes and posts. The connectors and 3?as shown are positioned on the sides of the bridge and are of a form toposition the crystal with its flat surfaces parallel to the flat wall ofthe holder 4 and positioned centrally therein as effected by the otherdisclosures.

Having described my invention, I claim:

1. A frequency determining unit of the character described having incombination a holder of insulating material formed with an internalsocket for the reception of a crystal mounting unit and a separablecrystal mounting unit having a support of insulating material providedwith combined connector and mounting member supports'secured thereto andspaced for bearing support on the holder and the said holder beingprovided with electrical terminal elements and securing means positionedto secure the connector supports and to effect electrical connectionwith the terminal elements.

2. A frequency determining unit of the character described comprising aholder of insulating material formed with an internal socket, a crystalmounting unit comprising a bridge mounting member of insulatingmaterial, combined electrical connector and mounting member supporssecured to the mounting member and formed with apertured extensionspositioned to overlie sidewall portions of the holder, electricalterminal elements fitted to the holder in alignment with the extensionapertures and securing screws fitted to the extension apertures andthreaded to the terminal elements for effecting electrical and securingconnection therewith.

3. A frequency determining unit of the character described comprising aholder of insulat ing material formed with an internal socket and sidewall recesses communicating with the socket and providing ledges indifferent horizontal planes, a crystal mounting unit comprising a bridgemounting member of insulating material, combined electrical connectorand mounting sup ports secured to the mounting member and formed withapertured extensions positioned to overlie the sidewall ledges of theholder, electrical terminal elements fitted to the holder in verticalalignment with the extension apertures and securing screws fitted to theextension apertures and threaded to the terminal elements for effectingelectrical and securing connection therewith.

4. A frequency determining unit of the character described comprising aholder of insulating material of substantially cylindrical form havingan internal socket and sidewall recesses communicating internally withthe socket and providing ledges in difierent horizontal planes, acrystal mounting unit comprising a bridge mounting member of insulatingmaterial, combined electrical connector and mounting supports secured tothe mounting member and formed with apertured extensions positioned tooverlie the sidewall ledges of the holder, electrical terminal elementsfitted to the holder in vertical alignment with the extension aperturesand securing screws fitted to the extension apertures and threaded tothe terminal elements for eliecting electrical and securing connectiontherewith and said offset planes of the ledges correspondingsubstantially to the thickness of the bridge mounting.

5. A frequency determining unit of the character described comprising aholder of insulating material formed with an internal socket for thereception of a crystal mounting unit and with spaced supporting ledgeportions, terminal pins positioned in the holder body to underlie theledges, a detachable crystal mounting unit comprising a bridge mountingmember of insulating material, combined electrical connector andmounting supports secured on the mounting member and spaced for bearingupport on the ledges, a crystal and electrodes therefor, crystalsupporting means carried by the mounting and electrically connected tothe connector and mounting supports and to the crystal electrodes andsecuring and connector screws fitted to apertures in the connectorsupports and the ledges and threaded to the terminal pins for securingof the mounting unit and to effect circuit connection with the pins.

6. A frequency determining unit of the character described comprising aholder of insulating material of substantially cylindrical form havingan internal socket for the reception of a crystal mounting unit andformed with opposite aligned supporting ledge portions, oppositelypositioned terminal pins received in the holder body sidewall tounderlie the ledges, a detachable crystal mounting unit comprising abridge mounting member of insulating material, combined electricalconnector and mounting supports secured on the mounting member andextended for bearing support on the ledges, a crystal and electrodestherefor, crystal supporting means carried by the mounting andelectrically connected to the connector and mounting supports and to thecrystal electrodes, securing and connector screws fitted to apertures inthe connector supports and the ledges and threaded to the terminal pinsfor securing of the mounting unit and to effect circuit connection withthe pins and said ledges being arranged in different horizontally spacedplanes having spacing substantially corresponding to the thickness ofthe bridge mounting.

'7. A frequency determining unit of the character described comprising aholder of insulating material formed with an internal socket for thereception of a crystal mounting unit and with opposite aligned ledges,terminal pins positioned in the holder body to underlie the ledges, adetachable crystal mounting unit comprising a bridge mounting member ofinsulating material, electrical connector and mounting supports securedon the mounting member and oppositely extended for bearing support onthe ledges, a crystal and electrodes therefor, crystal supporting meanscarried by the mounting and electrically connected to the connector andmounting supports and to the crystal electrodes, securing and connectorand mounting screws fitted to apertures in the connector supports andthe ledges and threaded to the terminal pins for securing of themounting unit and to effect circuit connection with the pins and saidledges being arranged in different horizontal planes spacedsubstantially to correspond to the thickness of the bridge mountings.

8. A frequency determining unit of the character described comprising aholder of insulating material formed with an internal socket for thereception of a crystal mounting unit and with spaced supporting ledgeportions, terminal pins positioned in the holder body to underlie theledges, a detachable crystal mounting unit comprising a bridge mountingmember of insulating material, electrical connector and mountingsupports secured on the upper and lower faces of themountingmember andoppositely extended for bearing support on the ledges, a crystal andelectrodes therefor crystal supporting means carried by the mounting andelectrically connected to the connector and mounting supports and to thecrystal electrodes and screws fitted to the apertures in the connectorand mounting supports and the ledges and threaded to the terminal pinsfor securing of the mounting unit and to eiTect circuit connection withthe pins and said ledges being arranged in different horizontal planesspaced substantially to correspond to the thickness of the bridgemounting.

9. A frequency determining unit of the character described comprising aholder of insulating material formed with an internal socket, a crystalmounting unit comprising a bridge mounting member of insulatingmaterial, electrical connector and mounting supports secured to themounting member and formed with apertured extensions positioned tooverlie sidewall portions of the holder, electrical terminal elementsfitted to the holder in alignment with the extension apertures andsecuring screws fitted to the extension apertures and threaded to theterminal elements for effecting electrical and securing connectiontherewith, a crystal and electrodes therefor, said mounting member beingformed with a multiplicity of spaced apertures therethrough for crystalsupporting posts and said connector and mounting supports being formedto overlie separate series of said apertures, opposite supporting postsfitted each within an aperture in electrical connection with a connectorand. mounting support.

10. A piezo-electric crystal structure comprising a rectangular crystalmounting unit of insulating material and a holder element havingexternally projecting electric terminals and provided internally withmeans for supporting said crystal mounting unit, said unit havingconductive terminals for connection to the crystal electrodes andconductive means secured to opposite sides of the unit connecting thelast-mentioned terminals to said projecting electric terminals andserving to attach said unit to said supporting means.

11. A frequency determining unit of the character described comprisingan insulating holder, a crystal mounting unit comprising a bridgemounting member of insulating material, combined electrical connectorand mounting member supports secured to the mounting member and formedwith apertured extensions, electrical terminal elements fitted to theholder in alignment with the extension apertures and securing meansfitted to the extension apertures and threaded to the terminal elementsfor effecting electrical and securing connection therewith.

SAMUEL ALEXANDER BOKOVOY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,978,188 Ciccolella Oct. 23,1934 2,203,486 Bond June 4, 1940

